1. Field of the Invention
This invention relates to an image reducing device and a method, and more particularly to an image reducing device and an image reducing method that convert image data into smaller image data with less pixels by simple-averaging and weighted-averaging.
2. Description of Related Art
When an image captured by an electronic camera with a high resolution is to be displayed on a display with a low resolution, the original image data is reduced to smaller image data. The reduced image data is stored in a display memory, or the original image data is read from the display memory to be converted into the reduced image data.
FIGS. 7(a), 7(b) and 7(c) show conventional image reducing methods. In FIG. 7(a), some of the pixels are removed. In FIG. 7(b), a simple average (arithmetic mean) of data of four adjacent pixels of each area is calculated to acquire a pixel of the reduced image data. In FIG. 7(c), a weighted average of data of pixels is calculated to acquire a pixel of the reduced image data.
However, in the first method, the reduced image is unclear. In the second method, the reduced image is blurred. In the third method, a memory with a large capacity is needed and much time is needed for calculation.
If some of the pixels of the original image data are removed before the simple-averaging or the weighted-averaging, the image is unclear like that in the first method.
Thus, the hardware and software may become overloaded in order to produce the reduced image data of high quality. In addition, edging is performed after the image data is reduced, and this lengthens the processing time.
It is therefore an object of the present invention to provide an image reducing device that can obtain a reduced image of high quality without overloading the hardware and software and also can perform edging at the same time, and an image reducing method.
To achieve the above object, the present invention provides an image reducing device that converts original image data into reduced image data with less pixels, the image reducing device comprising: a simple-averaging device that calculates a simple average of data of pixels of each simple-averaging area of the original image data to acquire a pixel of middle image data; and a weighted-averaging device that multiplies data of pixels of the middle image data that are adjacent to a pixel of the reduced image data by weight coefficients according to positions of the pixel of the reduced image data and the pixels of the middle image data to acquire the pixel of the reduce image data.
According to the present invention, the image reducing device comprises a simple-averaging device that calculates a simple average of the data of pixels of each simple-averaging area of the original image data to acquire a pixel of the middle image data, and a weighted-averaging device that multiplies the data of pixels of the middle image data that are adjacent to a pixel of the reduced image data by weight coefficients according to the positions of the pixel of the reduced image data and the pixels of the middle image data to acquire the pixel of the reduce image data. This can obtain a reduced image of high quality without overloading the software and hardware.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating Preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.